DirectionsPreheat the oven to 300 degrees.Line the baking sheets with parchment paper.Mix the butter, sugar, and vanilla using a mixer.Gradually blend in the flour and corn starch. Stir in 1 cup of M&M's.Form the dough into 1 inch balls and place on the baking sheets. Gently flatten each ball using your fingers or a flat bottomed drinking glass. If you use a drinking glass be sure to dip it into sugar so that the dough does not stick. Press in additional candies to decorate.Bake 25-30 minutes or until the bottoms begin to brown.Cool for 5 minutes then remove to a wire rack to cool completely.